| 摘要 |
Prodn. of a beta-keto-polyene alcohol of formula A-CH=CH-A' (Ia) or A'-CH=CH-B-CH=CH-A' (Ib) comprises reaction of a polyene aldehyde of formula A-CHO (IIa) or OHC-B-CHO (IIb) with a cyclocarbonate of formula (III) under basic conditions. A' = CO-CR1R2OH; A, B = opt. substd. conjugated polyene mono- or dialdehyde devoid of terminal CHO gp(s).; R1 = 1-6C alkyl; R2 = 1-6C alkyl or 2-6C alkenyl; or R<1>+R<2> = 1,4-tetramethylene or 1,5-pentamethylene. Beta-keto-polyene alcohols of formula R'-CH=CH-CO-C(CH3)2OH (Ic) and R"-CH=CH-CO-CR11R12OH (Id) are new. R', R" = gp. of formula a), b) or c); R, R4 = H, opt. protected OH or oxo; R5 in (Ic) = protected CHO or 4-hydroxy-4-methyl-3-oxo-1-pentyl; R5 in (Id) = protected CHO or CH=CH-A'; m = 0-4; n = 0 or 1; p, r = 0-2; q = 0-3; cpds. (Ic) are excluded when: i) R' = a), m = 2 or 3, R3 = H or opt. protected oxo, R4 = H and n = 0; ii) R' = a), m = 3, R3 = opt. protected OH, R4 = H or opt. protected oxo and n = 0; iii) R' = b), q = 3, p = 2 and n = 0; and iv) R' = c), r = 2 and n = 0; and cpds. (Id) are excluded when R6 = CH=CH-A' and R1 = R2 = Me. |
