STEREOSELECTIVE ACETYLATION OF RACEMIC ONYL)-N-(GUANIDINOHEPTANOYL)]-ALPHA-HYDROXYGLYCINE

Chiral intermediate nyl)-N-(guanidino-heptanoyl)]-alpha-acetoxyglycine 2 was prepared for the total synthesis of a (-)-15 deoxyspergualin, a n antitumor antibiotic and immunosuppressive agent. The stereoselectiv e acetylation of racemic onyl)-N-(guanidinoheptanoyl)]-alpha-hydroxygl ycine 1 was carried out in methyl ethyl ketone (MEK) using lipase from Pseudomonas sp. (lipase AK). Vinyl acetate was used as an acylating a gent. A reaction yield of 48% (theoretical max 50%) and an optical pur ity of 98% were obtained for S-(-)-acetate 2. The unreacted alcohol ()-1 was obtained in 41% yield and 93.5% optical purity. (C) 1997 Elsev ier Science Ltd.