Banca de DEFESA: PEDRO RAMOS DE SOUZA NETO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : PEDRO RAMOS DE SOUZA NETO
DATE: 25/07/2025
TIME: 09:30
LOCAL: Recife
TITLE:

STEREOSELECTIVE SYNTHESIS OF 2-DEOXY-2-HALO(IODO, FLUORINE)-α,β-D-O,N-GLYCOPYRANOSIDES FROM GLYCAL

KEY WORDS:

O-glycosides, 2-halo-desoxi-O-glucosides, DIDMH. SelectFlúor®.

PAGES: 491
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

This work aimed to synthesize and characterize novel O-glycosides and 2-halo-desoxi-O-glycosides from D-glycals with various primary alcohols. Initially, the compound BPSE 11 promoted the protection of tri-O-acetyl-D-glycal 12a to afford PSE-D-glycal 13a in 77% yield. Subsequently, the acetylation of PSE-D-glycal 13a was performed in 80% yield, followed by oxidation in 82% yield, and silylation to obtain TBDMS-O-PSE-D-glycal 13d in 96% yield. To obtain the O-glycosides, PSE-D-glycals 13a-b were reacted with the epoxidizing agents MCPBA and Oxone® in the presence of acetone under basic conditions, furnishing new compounds 14, 15a-b, 16a-b, and 17a-b in good yields. In parallel, tri-O-acetyl-D-galactal 12b was prepared in 52% yield, as well as di-O-acetyl-L-arabinal 12c. The 2,3-unsaturated compounds were prepared via the Ferrier rearrangement from D-glycals 12a-b using glycerol carbonate and propargyl alcohol promoted by BF3 or doped MK-10. Subsequently, a series of 2-deoxy-2-iodo-O,N-glycosides was prepared from D-glycals 12a-c and 13a,b,d using the iodine reagent DIDMH under reflux and microwave irradiation, affording excellent yields ranging from 6% to 85%. Finally, 2-flúoro-desoxi-O-glycosides were obtained from 3-O-TBDMS-PSE-D-glycal 13d and various alcohols using SelectFlúor®, obtaining moderate yields. In summary, 30 novel 2-halo-glycopyranoside compounds were obtained.

COMMITTEE MEMBERS:
Presidente - RONALDO NASCIMENTO DE OLIVEIRA
Interno - CELSO DE AMORIM CAMARA
Interno - JOAO RUFINO DE FREITAS FILHO
Externo ao Programa - 3022573 - JUCLEITON JOSE RUFINO DE FREITAS - UFRPEExterno ao Programa - 2002989 - ANDRE AUGUSTO PIMENTEL LIESEN NASCIMENTO - UFRPEExterna à Instituição - INGRID TRAJANO DE LIMA RAMOS
Externo à Instituição - ADILSON BEATRIZ - UFMS