Stereoselective synthesis of syn,syn-2-methyl-1,3-diols through one-pot aldol–reduction sequence
摘要:
Chx(2)BCl-inediated syn-aldol reaction of the alpha-OTBS lactate-derived ketone 1 followed by in situ reduction of the resulting boron aldolate with LiBH4 lead to complete stereoselectivity for the bororlates 2 in 80-95% yields. Then, a very mild oxidative work-up of 2 (H2O2/NaOAc in THF-H2O) allows isolation of syn,syn-2-methyl-1,3-diols 3 in yields up to 95% without migration of the TBS group. (C) 2002 Elsevier Science Ltd. All rights reserved.
α-tert-butyldimethylsilyloxy ketones followed by reduction of the resultant aldolates with LiBH4 provides a straightforward access to syn-1,3-diols. These diols, containing up to three new stereocentres, can be easily isolated in high yields after a simple work-up without any additional oxidative treatment, which confers to this procedure an appealing position to prepare stereoselectively such sort of structures