(4R)-4-Benzyl-3-{(4S)-4-chloro-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]butano­yl}-1,3-oxazolidin-2-one

The title compound, C₁₉H₂₄ClNO₅, was synthesized and subsequently employed in an Evans alkyl­ation. The purpose was to prove the absolute configuration in the projected synthesis of the side chain of (-)-Lytophilippine A. The oxazolidinone and the isopropylidene acetal rings have twisted conformations. The oxazolidinone and side-chain carbonyl groups are orientated in an anti­periplanar arrangement to minimize van der Waals repulsions. Furthermore, the Cl atom and the acetonide-protected secondary alcohol are also in an anti­periplanar arrangement with a torsion angle of 173.64 (14)°. The absolute configuration was determined and agrees with the configuration of the used chiral auxiliary.

Triphen­yl(prop-2-yn-1-yl)silane

In the title compound, C₂₁H₁₈Si, the coordination geometry around the Si atom is a slightly distorted tetra­hedron with C-Si-C angles in the range 106.05 (11) to 110.58 (10) ° and Si-C bond lengths in the range 1.855 (2) to 1.883 (3) Å. The alkyne C-C bond length is 1.167 (4) Å. The dihedral angles between the three phenyl rings are 63.89 (7), 86.38 (7) and 70.51 (8)°. In the crystal, mol­ecules inter­act only by van der Waals forces.