Tokyo Kasei Kogyo Co., Ltd.

The starting allyltrimethylsilane can be prepared in satisfactory yield by the procedure of Sommer. It can also be purchased from PCR Inc., Aldrich Chemical Company, Inc., Fluka A. G., Petrarch Systems Inc., and Tokyo Kasei Kogyo Co., Ltd. The checkers employed material from Petrarch. 

Tokyo Kasei Kogyo Co., Ltd. (TKK), See Tokyo Chemical Industry Co. Ltd. (Japan)... 

Tokyo Kasei Kogyo Co., Ltd. (TKK), See Tokyo Chemical hidustry Co. Ltd. (Japan), 189 Tokyo Olika Kogyo Co., Ltd., 189 Toluene, 129 Toluene-2,4-dianiine, 130 Toluene 2,4-diisocyanate, 130 Toluene sulfonic acid, 130 o-Tolidiiie, 129 o-Toluidiiie, 130 Toluidines, 130... 

Camphorsulfonic acid was purchased from Tokyo Kasei Kogyo Co., Ltd. (+)-10-Camphorsulfonic acid could be reduced to 0.1 equiv of the starting material with prolonged reaction time. The checkers used ( )-10-camphorsulfonic acid purchased from Aldrich Chemical Company, Inc. 

The checkers used cis- and traits-4-terf-butylcyclohexanol (36 64) obtained from E. Merck A G, Darmstadt, methyl sulfide obtained from Tokyo Kasei Kogyo Co., Ltd., and triethylamine obtained from Wako Pure Chemical Industries, Ltd., without further purification. 

Dehydroprogesterone (1) was purchased from Sigma Chemical Company and used without further purification. Cuprous bromide-dimethyl sulfide complex was prepared according to House s procedure.2 Hexamethyl-phosphoramide, chlorotrimethylsilane, and triethylamine were purchased from Tokyo Kasei Kogyo Co., Ltd., Japan and distilled from calcium hydride (CaH2>. Tetrahydrofuran (THF) was distilled from sodium-benzophenone ketyl immediately prior to use. Methylene chloride was distilled from phosphorus pentoxide (P2O5). 

A THF solution of methylmagnesium bromide was purchased from Tokyo Kasei Kogyo Co., Ltd., Japan and titrated with sec-butyl alcohol using 1,10-phenanthroline as indicator. Rapid addition might raise the internal temperature and use of excess methylmagnesium bromide would cause undesired methylation of the A-ring enone. 

The following chemicals were purchased from Kanto Chemical Co. Inc. and used as received neopentyl glycol, p-toluenesulfonic acid, sodium, and n-BuLi. N,N,N, N -Tetramethylethylenediamine was purchased from Aldrich Chemical Company, Inc. and distilled before use. 1,3-Dichloroacetone was obtained from Wacker Chemicals East Asia and used as received. Reagent grade benzene, pentane, ether, THE, tert-butyl alcohol, acetonitrile, and toluene were purchased from Wako Chemicals Industries Ltd. Benzene, pentane, and tert-butyl alcohol were distilled from CaH ether and THF from sodium benzophenone ketyl immediately before use acetonitrile successively from PjOj and anhydrous KjCOj and toluene from LiAlH. Potassium tert-butoxide and 2-cyclopenten-1-one were purchased from Tokyo Kasei Kogyo Co. Ltd. the ketone was distilled before use. 

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