Crystal structure of c-6-[N,N-bis(trimethylsilyl)amino]-5,6-dihydro-r-4-[(1′-hydroxy-1′-methyl)ethyl]-t-5-methyl-3-phenyl-4H-1,2-oxazine, ONC(CH)(CH)(CH)(C6H5)C(OH)(CH3)2(CH3)NSi(CH3)3Si(CH3)3