RICHARD NEELY'S An Accidental Woman , furnishes exactly the kind of well-written literary froth one requires when lolling on the Rehoboth sands, slickly glistening with Tropic-Tan diesel oil. It's the saga of "Little Sara Sunshine," a demure Cleveland copywriter working in a Big Apple ad agency, whose entire personality changes radically after brain surgery. One slip of her neurosurgeon's scalpel, and virginal Sara Vardon metamorphoses into a voluptuous tigress stalking the boardroom by day and the bedroom by night. She becomes every man's nightmare/fantasy of the truly liberated corporate woman who stops at nothing to get satisfaction in her career and in her bed. Neely revels in his creation's "unfeminine" success and drive; thankfully he doesn't offer any Mildred Pierce retribution of her to suffer. In the end, Sara jets off with a tycoon just as tough and amoral as herself. Knitting no baby booties, she is pregnant only with plans to conquer new corporate citadels.

The rest of the novel's characters are just as flamboyant and amusing. Head of his own ad agency, hard-drinking hard-driving Brooks Madden is blessed with the moral fiber of an early Celtic saint. An aging film star, Maria Corliss, wins his heart, in part thanks to her surgically re-sculptured physique. Sparing no cliche, the author includes a psychotic executive secretary, Thea Roland, who provides a potpourri of services for her boss, the formidable Harry Dalton -- equal parts "ah shucks" Jimmy Stewart and the early airborne Howard Hughes. Rounding out the cast is the toadish Rich Bradley who inspires breathless ardor in the superior Sara: "He still loved her. She had not lost him, not forever. She would get him back somehow. No matter how long it took. Nothing could stop her."

Surprisingly, the oily machinations of corporate advertising grip the reader. We genuinely care that tough, craggy, ole Brooks retain control of his agency, that Thea's video espionage be unmasked, and that Sara and Harry fly off into the sunset of corporate ecstasy. For a relaxing weekend at the beach, who could ask for more? A CLOWN IN THE MOONLIGHT. By James Howard Kunstler. St. Martin's. 218 pp. $10.95

JAMES HOWARD KUNSTLER'Ss A Clown in the Moonlight chronicles the rather sad antics of one Richie Schuster, a junior professor of American literature teaching at a Bennington-like college nestled in Vermont. In the course of the novel, Richie loses his wife, his job, his best friend, and a very large chunk of his innocense as well.

Although a clever writer capable of creating some very funny comic situations, Kunstler fails to make believable the pivotal relationship between Richie and his wife Sally. Apparently aware of his failure, the author provides the rather lame excuse that "If these details shed insufficient light on her true nature, or fail to uncover those hidden wellsprings which animated her, which directed her mysterious movements, then you will know as much as I do, or neither of us will ever know." Granting the limitations of the first-person narration, the reader must still demand a stronger characterization of Sally than Kunstler offers. The reasons she and Richie tie and untie the nuptial knot never ring true. Their facile break-up comes off as a mechanical plotting device, one needed to get the ever-libidinous Richie into the more exotic bed of his student Dudley Roper: "No, not a little blonde-haired Protestant schoolboy. Not a sheep either. Far from it. . .Dudley was a girl. No, check that. Dudley was a woman. No, check that too. Dudley was a sort of bouquet garni of hormones wrapped up in the body of a woman with the mind of a willful little girl."

Kunstler certainly captures the lechery of well-educated American males who upon turning 30 suddenly yearn for teen-aged girls' "peach-cleft bottoms" Schuster's liaison with "that five-foot-three bundle of wantonness" leads to some compelling if rather disturbing imagery: "I gluttonized her fabulous body, like a hyena snorfling over the carcass of a young gazelle . . ."

The book also conveys the mythic allure that "the country" exerts over a sizeable contingent of the '60s generation who never quite made it to the commune. In grimy city apartments, they fondle L. L. Bean catalogs, diagram rhubarb plots, and devour such articles as "how to dig your own root cellar." They envision "the country" as an academic arcadia, complete with a " 'general store' where you can get a bag of bagels, a half-pound of first-class Nova, and the Sunday New York Times ."

Neither the country life nor the collegiate turn out to be what Richie and Sally expected. Satirizing faculty cocktail parties where soused senior professors ogle the wives of their junior colleagues, Kunstler points out that despite the plethora of PhDs, an awful lot of skullduggery still goes on in the ivory tower. Unfortunately, when Kunstler tries to do without the leavening agent of humor, the results are rather flat: "Annie is a good woman . . . Where Sally was tough, Annie is tender. Where Sally was a wise guy, Annie is a partner. . ." Perhaps the "general store" was having a sale on "country" wives?

A flawed but interesting novel, A clown in the Midnight suggests that Kunstler is a talented writer, and should prove interesting to watch in the future. GOODBYE, JANETTE. By Harold Robbins. Simon and Schuster. 419 pp. $12.95

IN HIS LATEST blockbuster, Goodbye, Jarnette , Harold Robbins has branched down, so to speak, into the nether regions of sado-masochism. The results are most upleasant, and worse still, rather dull. A long plough rather than a quick read, the book fairly yelps to be put down unfinished, or better yet, not started.

Goodbye, Janette commences with Tanya, a Polish countess, who through various contretemps including World War II, a stay in concentration camp, and being violated by several battalions, still manages to land a plum spot with a German general, both in and out of his bed. After the war, she hitches up with a depraved French marquis, who seems to have sprung from the same murky gene pool as the Marquis de Sade. Shrieking such original theories as "without pain there is no pleasure," he continues, and indeed expands upon, his unappetizing hobbies with his nubile stepdaughter, Janette, who grows up to be a real chip off the old block. However, when not lashing and slashing each other, the family manages to amass quite a tidy fortune in the perfume and clothing business.

Needless to say, exotic drugs, lurid sex, and mysterious Swiss beauty clinics play a massive, nay monumental role in the novel. Robbins adds to his literary stew a large, frankly indigestible chunk of "haute couture," and spices it with authentic fashion designer names like Dior and Yves St. Laurent. Libel suits could be in order. Towards the end, the author tosses in a third woman, a druggy little California blonde who wanders around murmuring "wow" and is too boring to describe, much less read about.

Amazingly, Harold Robbins makes the jetset world of high fashion and decadent aristocrats seem rather dull; I found myself positively pitying the characters. Kalamazoo sounds like more fun. GOLDENEYE. By Malcolm Macdonald. Knopf. 504 pp. $14.95

FOR FAMILY SAGA aficionados, Malcolm Macdonald's new novel, Goldeneye, offers up a rich literary feast of summer reading. It's the story of Catherine Hamilton, an auburn-tressed Scotswoman who flees her isolated croft, Beinn Uidhe, after the First World War to escape her father, An Doitean (Gaelic for "the great fire"), whose passionate love for his beautiful daughter has created unbearable tensions between the two.

Throughout the novel, Macdonald depicts the lilting accents and stark beauty of the Scottish coast, but through the filter of Catherine's memory, for we meet her as she leaves Scotland. Thirsting for experience, this feisty heroine travels across the Atlantic and half of Canada to join her Uncle Murdo on his prairie farm. But in the early years of the 20th century, the Spanish influenza took more lives than the Great War. Right off the train, Catherine finds herself nursing Murdo, his family, and half of Goldeneye besides. Falling in love with the older Dr. Macrae, she marries instead his son, the tempestuous Burgo who spends his life struggling to blot out his father's impressive shadow.

Their fruitful union brings forth both children and heartbreak, as the saga takes the couple through separation, the Great Depression, World War II, and perhaps the biggest obstacle of all, Burgo's overwhelming material success. At the very end of the book, Catherine still challenges her husband: "Now d'you know what sort of woman you married?"

In a frightening blizzard episode, Catherine and Dr. Macrae almost freeze to death as Macdonald reveals the huge, impersonal power of the Canadian winter. In a sense, Goldeneye continues the typically Canadian theme of survival before all else.

A long plunge into another world, of not so long ago, Macdonald's novel presents a portrait of a time, when life was harder and passions more lasting.