I found this about the eldest boy:
AGUSTIN MARIA MUÑOZ AND BOURBON.
Born in Madrid on March 15 1837, and died on July 15 1855. He was named Duke of Tarancon, Grande of Spain 1st Class, on November 19 of 1847, and in 1849, Viscount of Rostrollano. Ddue to his young age he died without offspring.
On this child, it is noteworthy that Gen. Juan José Flores, first president of the Republic of Ecuador, intended to set up a throne for him on Ecuador. Jorge Francisco Saenz Carbonell says that "Both the Queen Maria Cristina and the Duke of Riánsares received with great interest the proposal of Flores to erect a throne in Quito, especially as the skilful Venezuelan told them the possibility that the Ecuadorian hypothetical crown would go to one of their children, specifically to the nine year old Don Agustin Munoz and Bourbon. Dona Maria Cristina and her husband, who already were convinced in the idea of a new dynasty, began to help Flores in secret to organize expeditionary forces, with the knowledge of the Minister of War. Unfortunately for the designs of the Queen Mother and the Duke, the news was leaked, and in August 1846 a newspaper in Madrid, "El clamor publico", made the news of general knowledge. In Spain, there was a bitter controversy, and in many countries of Latin America there was a huge scandal. Plenipotentiary of Bolivia, Chile, Ecuador, New Granada and Peru came together to condemn the initiative. In the end, the Spanish government had to say that they had no part in the plans and Britain also got part into the matter. Flores had few ships in the estuary of the River Thames to board his soldiers but they were seized by the British authorities, and they also opened proceedings against Captain Richard Wright, who had been commissioned to organize the small square. At the end part of the Spanish Government had to resign and the prestige of Dona Maria Cristina was very damaged. "The reign of" Don Agustin I "and the dynasty Munoz finished before it started, and the child that was to be the King had to settle for the title of Duke of Tarancon, which was given to him by his half-sister Queen Isabel II in November 1847. He died unmarried in Paris in 1855, at eighteen years old, and the adventure was only an illusion.
And about the younger ones:
FERNANDO DE BOURBON AND MUÑOZ, born in Madrid on April 27 1838, and died on Dec. 7 1910. He was named first in 1848, I Count of Casa Muñoz, then in 1849, I Viscount of Arboleda, and after the death of his brother, II DUKE OF RIÁNSARES AND II DUKE OF TARANCÓN. He was married on September 11, 1861, in Oviedo, with Eladia Bernalda of Quiros and Gonzalez de Cienfuegos. They had eleven children.
JUAN BAUTISTA MARIA MUÑOZ AND BOURBON, born in Paris on August 29 1844, and died on April 2 1863, in Pisa. He was appointed Count of Recuerdo, 29 February 1848, and in 1849, the Viscount of Villarrubia I and II DUKE OF Montmorot. He had no offspring.
ANTONIO DE PADUA MUÑOZ AND BOURBON, born in Paris on December 23 1842, and died in Madrid in 1847.
JOSE MARIA MUÑOZ AND BOURBON, born in Paris on December 21 1846, and died in Pau, on Dec. 7 1863. . He was named Count of Gracia, 29 February 1848, and I Count of Arboleda. He had no offspring.