(3R,4S)-2-Oxo-3-oxhydryl-4-phenyl-1-boc-azetidine is an intermediate in the preparation of Paclitaxel (P132500), a neoplasm inhibitor used to treat patients with lung, ovarian, breast cancer, head and neck cancer, and advanced forms of Kaposi’s sarcoma. Paclitaxel is a mitotic inhibitor used in cancer chemotherapy.