Steric determinants in diastereocontrol during Baylis–Hillman reaction of sugar-derived aldehydes

Diastereoselective Baylis–Hillman reaction using different sugar-derived aldehydes with various activated olefins afforded chiral multifunctional adducts in good yields. Steric factors that dictate and determine the diastereoselection will be discussed.

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Ethyl 2-[2,2-dimethyl-(4R)-1,3-dioxolan-4-yl(hydroxy)methyl]acrylateC11H18O5[α]D = −6.4 (c 1.00, CHCl3)Absolute configuration: 4R

Ethyl 2-[2,2-dimethyl-(4S)-1,3-dioxolan-4-yl(hydroxy)methyl]acrylateC11H18O5[α]D = +6.2 (c 1.00, CHCl3)Absolute configuration: 4S

Ethyl-2-hydroxy[6-hydroxy-2,2-dimethyl-(3aS,5R,6R,6aS)-perhydrofuro[2,3-d][1,3]dioxol-5-yl]methylacrylateC13H20O7[α]D = −14.4 (c 0.10, CHCl3)Absolute configuration: (3aS,5R,6R,6aS)

Ethyl-2-hydroxy[6-hydroxy-2,2-dimethyl-(3aR,5S,6S,6aR)-perhydrofuro[2,3-d][1,3]dioxol-5-yl]methylacrylateC13H20O7[α]D = +14.4 (c 0.10, CHCl3)Absolute configuration: (3aR,5S,6S,6aR)

Ethyl-2-hydroxy[6-methoxy-5-methoxymethyl-2,2-dimethyl-(3aS,5R,6R,6aS)-perhydrofuro[2,3-d][1,3]dioxol-3-yl]methylacrylateC17H26O8[α]D = +0.9 (c 0.85, CHCl3)Absolute configuration: (3aS,5R,6R,6aS)