Syntheses of N6‐desmethylpuromycin (6), of 3′‐L‐homocitrullylamino‐3′‐deoxyadenosine (3) and its L‐lysyl analog 4 are reported, based on a preparatively efficient procedure for the preparation of 3′‐amino‐3′‐deoxyadenosine (2) from D‐xylose, and on attachment of the corresponding amino acid components via the N‐benzyloxycarbonyl‐blocked N ‐hydroxysuccinimidyl and p‐nitrophenyl derivatives Z,Z‐Lys‐OSU (18), Z‐Phe(OMe)‐OSU (20) and Z‐hCit‐ONP (23), each characterized in crystalline form. – Synthetic 3 was identical with the product isolated previously from Cordyceps militaris, thus now unequivocally establishing its structure. – In biological evaluation, 3 and 4 exhibited inhibition of poly (U) directed polyphenylalanine synthesis analogous to that of puromycin (5), yet lower by factors of 20 and 40, respectively, whilst that of 6 was identical with 5 qualitatively and quantitatively; hence, the N6‐methyl groups in 5 are not essential for termination of ribosomal peptide chain elongation.