Abstract The Claisen rearrangement of the N-protected, silylated allyl glycinates 11 and 12 led to the formation of allyl/silyl-functionalized amino acids 13 and 14 in yields up to 80%. The diastereoisomer ratio varied from 2: 1 to 29: 1 for 11mb, and from 2: 1 to 46: 1 (syn/anti) for 12mb, depending on reaction conditions, as shown by X-ray crystallographic analysis of 14mb. The relationship between the size of the alkyl groups on the chlorosilane reagent ( ...