Aldehydes stereoselectivity

S. Deloisy, T. T. Thang, A. Olesker, and G. Lukaes, Synthesis of a-azido aldehydes. Stereoselective formal access to the immunosuppressant myriocin. Tetrahedron Lett. 55 4783 (1994). 

Stereoselective Addition of Dialkylzincs to Chiral Aldehydes. Stereoselective addition of dibutylzinc to racemic 2-phenylpropanal using (1S,2J )-DBNE as a chiral catalyst affords optically active alcohols (84% ee, 92% ee) as a result of the si face attack of the aldehyde regardless of its configuration (eq 21). ... 

Allylsilanes attack cyclohexanone ketals axially (93 7) and attack 2-phenylpropionaldehyde acetal with a degree of Cram selectivity that is influenced by the choice of Lewis acid, tin(IV) chloride giving the highest ratio (3.5 1). ° With -alkoxyacetals, chelation control is not possible as it is with the corresponding aldehydes stereoselectivity is not high, it is in the opposite sense (Scheme 41, compare Scheme 16), and it depends upon the choice of Lewis acid. °... 

S. Deloisy, T. T. Thang, A. Olesker, and G. Lukacs, Synthesis of a-azido aldehydes. Stereoselective formal access to the immunosuppressant myriocin. Tetrahedron Lett. 35A7S3 (1994). P. C. Bulman Page, M. B. van Niel, and J. C. Prodger, Synthetic uses of 1,3-dithiane grouping from 1977 to 1988, Tetrahedron 45-.7M3 (1989). 

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