Table 1.

^a Variations in Carbinol Substitution.

entry	comp'd	product	yield, %b	drc	ee, %d
1	a		65	89:11	92
2	b		71e	88:12	92
3	c		70	92:8	92
4	d		55e	93:7	93

^aReaction conducted with 17 (0.50 mmol, 1.0 equiv), 6 (0.60 mmol, 1.2 equiv) and Rh₂(R-DOSP)₄ (0.0005 mmol, 0.1 mol %), unless otherwise indicated.

^bIsolated yield of the major diastereomer.

^cDetermined by ¹H NMR analysis of the crude reaction residue.

^dDetermined by HPLC analysis on a chiral stationary phase.

^eYield of the reaction with 0.5 mol % Rh₂(R-DOSP)₄.